Lighthouse
An open-source extension that audits the speed and quality of any page you are on.
Why it's a strong pick
Lighthouse works on any page, not on one framework. It is open source under the Apache-2.0 license, and its code is public on GitHub. It uses Manifest V3, Chrome's current extension format. The Lighthouse project made its latest release in September 2026.
What it does
Open a page, click the Lighthouse icon and run an audit from the popup. Lighthouse checks the page for performance, quality and correctness, then shows a report. The README says the extension came before Lighthouse in Chrome DevTools and offers similar functions.
Key features
- Popup audits. Run a check on the current page from the toolbar.
- Performance checks. See how the page performs.
- Quality and correctness checks. Find best-practice problems.
- Narrow permissions. It asks for activeTab and storage, with no host permissions listed.
- Open source. The code is public under Apache-2.0.
Who it's for
Lighthouse is for developers, SEOs and site owners who want to check page speed and best practices. You do not need to build the site to use it. You only need a page to test.
What permissions does Lighthouse ask for?
Its manifest asks for activeTab and storage, and lists no host permissions. It needs Chrome 88 or newer. That is a short list for a developer tool. The README also says Lighthouse runs locally and that report results are never processed or beaconed to a remote server.
Do I need the extension if Chrome already has Lighthouse?
For most people, no. The README says the extension predates Lighthouse in Chrome DevTools and offers similar functions. Use the DevTools panel if you already work there. The extension is mainly useful when you prefer to start an audit from a popup.
Does it show how real visitors see my page?
No. Lighthouse runs a test on your own machine, so it gives lab data, not data from real visitors. Treat the score as a guide for finding problems. Your results can change between runs and between computers, so compare like with like.
FAQ
Is it only for developers? No. SEOs and site owners can run it too.
Does it work on any site? It audits the current page, so it is not tied to one framework or site.
Is it open source? Yes, under the Apache-2.0 license.
Good to know
Run the audit two or three times and look at the pattern, not one score. Close other heavy tabs first, since the test runs on your own computer. Fix the biggest items the report lists before you chase small ones.
Other developer tools to compare
Lighthouse is one of 13 picks in our developer tools guide:
- JSON Formatter: read JSON responses.
- Redux DevTools: debug Redux state.
- Apollo Client Devtools: inspect Apollo Client apps.
- Preact Developer Tools: inspect Preact components.
- React Developer Tools: inspect React components.
- Vue.js devtools: inspect Vue 3 apps.
- Requestly: Open-source HTTP interceptor: redirect URLs, modify headers and mock requests while you test.
- Solid DevTools: debug SolidJS reactivity.
- Ember Inspector: inspect Ember.js apps.
- MobX Developer Tools: debug MobX apps.
- Refined GitHub: Simplifies GitHub and adds 100+ small improvements for repos and pull requests. Works on GitHub.com only. Open source.
- Header Editor: Rewrites request and response headers, redirects and blocks requests with rules you set. The Chrome build is the Lite version. Open source.
This is a third-party extension, not built or maintained by Xplorekit. We link to the official Chrome Web Store listing — install and permissions are entirely between you and the extension's own publisher.